• Hello Guest, we are proud to now have our Wiki online that is completely compiled and written by our members. Feel free to browse our Jeep-CJ Wiki or click on any orange keyword when looking at posts in the forum.

BEST in tank fuel pump and sender for GM TBI on cj7 jeep!

BEST in tank fuel pump and sender for GM TBI on cj7 jeep!
Shifter said:
I missed this post earlier...

I just put an in tank pump but for a tuned port, just different pump.
I used a Bosch pump...you could just get one for a chevy pickup with a tbi engine.
The pickup in your sending unit is 5/16" same size as output on pump. Cut the tube so your pump will be just off bottom of tank... 1/16"-1/8". Use the good fuel injection clams to hold the pump on... It won't go anywhere.

I then ran the wires out the 1/4 return line fitting and sealed with a fuel resistant silicone... Jb weld would work also.

I just fired it up yesterday... Works like a champ. Pump was $64 screen about $6 through rock auto. Oem quality. :chug:

4A0DF856-4BE3-4D12-A953-5C7F78F025C0.webp
Click to expand...


hi shifter... thanks for your response and pic.. after seeing all the great mods for intank fuel pump.. i decided to give it a go..

a couple of questions:
did you just run the wires through the 1/4" hole you drilled? or did you us a screw with nylon washers like for the stock fuel sending unit wire?
if you were to use shoulder washers etc,,, any ideas on how to arrange them and make it the safest so as to not allow the electric fuel pump power wire to ground out on the metal fuel sender unit top plate? if i didn't insulate it well enough is it possible to cause an explosion or will i just ground out the sending unit or blow out fuel pump fuse or kill the fuel pump itself?

your help is much appreciated! :cool:
 
another question!


my gm fuel pump appears to be magnetic... what does that mean in my polyurethane tank? is it okay? should i have a insulator over the pump or not?

:confused:
 
I fed the power and ground wires for the pump out through the 1/4" return line on the sender, because I was not using it. I then sealed it with fuel proof silicone. Any sealer that will withstand fuel will work also.

To do a proper insulator, there needs to be a shoulder on the washer to protrude through the hole, then another non conductive washer on the topside.

If your power wire shorts out to the sender, it should blow the fuse if you have one.... But it could also go kaboom...:eek:
 
If you do your pump power wire the same way the sending unit wire is done, you will be good. You want infinite resistance between pump power wire and sender body. Check this with the ground wire for pump unhooked, otherwise you will read the resistance of the pump. ( just unhook the pump when doing resistance check )
 
Shifter said:
I fed the power and ground wires for the pump out through the 1/4" return line on the sender, because I was not using it. I then sealed it with fuel proof silicone. Any sealer that will withstand fuel will work also.

To do a proper insulator, there needs to be a shoulder on the washer to protrude through the hole, then another non conductive washer on the topside.

If your power wire shorts out to the sender, it should blow the fuse if you have one.... But it could also go kaboom...:eek:
Click to expand...


Me soooooo scared:confused:.... Thanks shifter for your quick response... :notworthy:

I may just drill a larger hole and then put a connector through it that was on another fuel sending unit... Just cause I don't want to die young... :o
 
Shifter said:
If you do your pump power wire the same way the sending unit wire is done, you will be good. You want infinite resistance between pump power wire and sender body. Check this with the ground wire for pump unhooked, otherwise you will read the resistance of the pump. ( just unhook the pump when doing resistance check )
Click to expand...



Ur... Just to clarify... What should the ohms read? :confused: ... :o
"1" .... Correct?
 
Shifter said:
The pump being magnetic does not matter in a plastic tank.
Click to expand...


Good to know! Why the pump magnetic? If ya know....
So, If it was a metal tank, I would need the insulator/sleeve then? :rolleyes:
 
76cj7chick said:
Ur... Just to clarify... What should the ohms read? :confused: ... :o
"1" .... Correct?
Click to expand...

No.. You want it to read open.. As in no connection...the same as if you hold one test lead in the right hand... And the other in your left hand.
 
76cj7chick said:
Good to know! Why the pump magnetic? If ya know....
So, If it was a metal tank, I would need the insulator/sleeve then? :rolleyes:
Click to expand...

The pump is magnetic because it is a permanent magnet motor.. That's one design of a dc motor.
The sleeve is a spacer/ noise insulator for when the pump goes into a fuel module in the newer tanks.
 
Just a follow up..
I purchased a "cheap" in tank fuel pump off e--y... And although the fuel pressure is 15psi at the pump.. It drops down to 8-9psi at the throttle body... :(
Plus, the pump is so cheap that it doesn't hold the pressure.. Once the engine is shut off the pressure falls quickly to zero.. :mad:

On the good side... The in tank design is so far working but just need a better pump.. I'm looking to get a better made pump... But that only has 12-15psi AT the throttle body...
I currently have 5/16" outlet and return fuel lines...

If anyone knows of a quality somewhat economical in tank (1.5"ish diameter) fuel pump, please let me know what part number to look for...

I've been looking at walbro's 5CA401... This is equivalent to their Walbro GLS953 external pump... (which I like the gls but want/need intank... )
 
Congrats on the fuel pump hookup. I am still trying to survive with mine mounted on the frame. BTW, you did know that the tbi fuel pressure is adjustable at the regulator from underneath didn't you? Another critical item is that the fuel tank vent system must have enough air in it for the pump to work properly. Make sure you are getting full battery voltage at the pump during operation also. As for you pump selection, calling Summit Racing or Walbro might get you some good tech info.
 
Hmmmmm..I didn't know that the throttle body had an adjustable regulator... :0

I think the problem is the current fuel pump, as when I had an inline fuel pump everything seemed to work fine... I've decided it is easier and cleaner to switch to an intank pump... Easier in the sense that I just made an "access panel" in my jeep tub so I can get to the sending unit easy and don't have to drop the tank.. :p But, if I get another pump and experience the same issue, I will look into adjusting the regulator... Thanks for your help. :)
 
If you look at the underneath of the tbi, between the inlet and outlet fuel lines there is an adjustment requiring a flat head driver. I am sure you could find more info online about it.
 
Good to know thanks for the help. :)
 
By the way... In a previous post I said my inline pump was Walbro GLS953... But the correct pump I was using is walbro Gls395...
Just need an in tank fuel pump that is equivalent to the walbro's...


So... Please let me know if you know of a good in tank pump that holds 12-15psi at the throttle body..

;)
 
You must log in or register to reply here.

Jeep-CJ Donation Drive

Help support Jeep-CJ.com by making a contribution.

Help support Jeep-CJ.com by making a contribution.
Goal
$200.00
Earned
$25.00
This donation drive ends in
0 hours, 0 minutes, 0 seconds
  12.5%
Contribute
Back
Top Bottom